Picosecond Relaxation of 3MLCT Excited States of [Re(Etpy)(CO)3(dmb)]+ and [Re(Cl)(CO)3(bpy)] as Revealed by Time-Resolved Resonance Raman, UV−vis, and IR Absorption Spectroscopy
| Autor: | Pavel Matousek, M. Towrie, Davina J. Liard, Michael Busby, Antonín Vlček |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 108:2363-2369 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp0366320 |
| Popis: | Picosecond dynamics of Re → polypyridine 3MLCT excited states of [Re(Etpy)(CO)3(dmb)]+ and [Re(Cl)(CO)3(bpy)] were investigated by time-resolved UV−vis, resonance Raman, and IR spectroscopy. Raman bands due to NN•- intraligand vibrations of the excited molecules increase with time during the first 15−20 ps after excitation. The time constant of 6 ± 2 ps was estimated for the increase of areas of excited-state Raman bands of [Re(Etpy)(CO)3(dmb)]+. The growth of Raman bands is accompanied by an increase of the near-UV transient absorption band at 375 nm, which corresponds to a ππ* transition of the dmb•- ligand of the 3MLCT excited state [ReII(Etpy)(CO)3(dmb•-)]+. These effects are attributed to structural reorganization during vibrational cooling, during which the electronic dipole moment and/or vibrational overlap integrals increase. IR bands due to CO stretching vibrations and some of the Raman bands undergo dynamical upward shift and narrowing, that occur with time constants between 1 and 11 ps, manifes... |
| Databáze: | OpenAIRE |
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